Microsoft Defender Zero Day RoguePlanet: When Your Detector Becomes the Attack Surface

**RoguePlanet (CVE-2026-50656)** is a Microsoft Defender privilege-escalation zero-day in the Microsoft Malware Protection Engine that can yield SYSTEM-level command shells; a proof-of-concept was published and reportedly works whether Defender real-time protection is enabled or not, Microsoft has confirmed the issue and a patch is pending, and the report urges adding prevention-first controls and rapid patching to mitigate the active exposure window.